Pump



United States Patent a corporation of @hio Filed June 3, 1964, Ser. No. 372,163 18 Claims. (Cl. 1ll3175) This invention relates to pumps, and more particularly to plunger type pumps.

Among the several objects of this invention may be noted the provision of a plunger type pump especially suitable for pumping materials of nonlubricating quality which has low friction characteristics; the provision of a pump such as described having a relatively short pump tube or cylinder; the provision of a pump such as described which is double-acting and operable to pump material without objectionable pulsation; and the provision of a pump such as described which is economical to manufacture and reliable and long-lasting in use. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated,

FIG. 1 is a plan view of a pump of this invention;

FIG. 2 is a longitudinal cross section taken on line 22 of FIG. 1;

FIG. 3 is a transverse cross section taken on line 33 of FIG. 2; and

FIG. 4 is a fragmentary cross section showing a modification.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring first to FIGS. 1-3 of the drawings, a pump of this invention is shown to comprise a pump tube or cylinder generally designated 1. Within the cylinder intermediate the length of the cylinder is mounted an annular valve seat 3. This seat is coaxial with the cylinder and, in effect, divides the cylinder into a first chamber 5 (which is the upper chamber as viewed in FIG. 2) and a second chamber 7 (which is the lower chamber as viewed in FIG. 2). Chambers 5 and 7 are of substantially equal size. At 9 is indicated a valve located in the first chamber at its lower end engageable with the seat to close 011 communication between the chambers. This valve is adapted to open as a result of pressure differential between the second chamber and the first chamber. The cylinder has a checked inlet 11 at its lower end for admission to the lower chamber of material to be pumped, and a lateral outlet 13 from the upper chamber. At 15 is indicated a stepped plunger reciprocable in cylinder 1 and having a first (upper) cylindric section 17 and a second (lower) cylindric sec tion 19, the latter being of larger diameter than section 17. Section 19 extends slidably through a central hole in the valve 9, having a sliding sealing fit therein, and through the central aperture of annular valve seat 3. The latter aperture is of larger diameter than section 19 to provide an annular passage around section 19 for flow of material from chamber 7 to chamber 5 on downstrokes of the plunger. Plunger section 19 may have twice the cross sectional area of plunger section 17, for example.

The cylinder 1 comprises a tubular section 21 which defines the lower chamber 7. Threaded on the upper end of section 21 is a body 23 formed to provide a tubular extension 25 of section 21 and to define the upper chamber 5. The body 23 has a lateral extension 27 formed to provide the lateral outlet 13 from chamber 5. As shown at 29, a valve is provided for priming purposes.

Threaded in the upper end of the tubular extension 25 is a tubular insert or head 31 carrying a bushing 33 for guiding the upper section 17 of plunger 15. Packing for insert 31 is shown at 35, and packing for section 17 of the plunger is indicated at 37.

The upper end of section 21 of the cylinder 1 is countersunk as indicated at 39. The periphery of seat 3 is preferably made of spherical form for accurate seating on the counters-ink 3-9. The seat 3 has a fiat upper face 11 engageable by the valve 9 to close the passage through the seat. Extension 25 has an annular shoulder 43 adjacent .its lower end engaging the rim of seat 3 to hold it in place. Packing between extension 25 and cylinder section 21 is indicated at 45.

As shown in FIG. 3, valve 9 is generally of square cross section, having a clearance fit in the bore of cylinder extension 25 and providing spaces or passages 47 between the perimeter of the valve and the bore for flow of material up into chamber 5 when the valve is off seat 3. The four corners of the valve are grooved as indicated at 48 to facilitate fiow past the valve when it is open. Packing constituted by an O-ring 0 received in an internal groove in the valve provides for the sliding sealing fit of plunger section 19 in the valve. It is possible that parts 9 and 19 could be lapped for a lapped sliding sealing fit.

A shoulder 49 in the tubular extension 25 of the cylinder is axially space-d from the shoulder 43 and on the opposite side of the valve 9. The shoulder 49 is engaged by the edges or corners of the valve when the valve is moved upwardly off the seat 3 thereby limiting upward (opening) movement of the valve. Another shoulder 51 in the tubular extension 25 of the cylinder is spaced axially from the shoulders 43 and 49. A coil spring 53 reacts from the shoulder 51 against the valve 9 biasing the valve toward engagement with the seat 3 for closing off communication between chambers 5 and 7.

A collar 55 is threaded on the lower end of lower cylinder section 21 and projects downward therefrom. The checked inlet comprises an annular seat 57 for a ball check valve 59 held against the lower end of cylinder section 21 by a tubular cylinder extension 61 threaded upward in the collar. Extension 6 1 has spanner wrench holes 63 at its lower end. Ball check valve 59 is held captive in a retainer es held against a shoulder 6-7 in cylinder section 21 by the valve seat 57. Packing 59 is provided between seat 57 and the retainer.

A flange 71 on collar 55 has an inclined hole 73 therethrough. A sleeve 75 is threaded in this hole from the top of the flange and a probe rod 77 is pinned in the sleeve 75 by a pin 79 and projects through the collar 55. Flange 71 is adapted for attachment to a follower for pressing down on material to be pumped contained in a drum, and rod 77 is adapted, on unscrewing sleeve 75 from the flange, to be inserted through hole 73 and a registering hole in the follower and manipulated to assist in venting of air from under the follower through the pump. The pin serves as a handle for this purpose.

Operation of the above-described pump is as follows:

The plunger 15 is reciprocated up and down in the cylinder 1 by suitable means, such as an air motor (not shown) connected to the upper end of the plunger. FIG. 2 shows the plunger at the end of a downstroke. On each upstroke of the plunger, ball check 59 opens and material to be pumped is drawn into lower chamber 7 of the pump cylinder 1. Section 19 of the plunger moves up into the upper pump chamber 5, valve 9 remaining closed on valve seat 3 under the bias of spring 53 and pressure .in chamber 5. Since plunger section 19 is of larger cross-sectional area than plunger section 17, a quantity of material is displaced from chamber 5 and forced out through the pump outlet 13 (assuming chamber 5 is primed). The amount of material delivered corresponds to the difference in volume of plunger sections 17 and 19.

On each downstroke of the plunger, plunger section 19 slides down through the valve 9 into the lower pump chamber 7. Ball check 59 closes under pressure induced by plunger section 19. Valve 9 opens (moves upward off seat 3) against the bias of spring 53 under the pressure ditferential existing between chambers 7 and 5, and plunger section 19 displaces material from chamber 7 through the annular passage around plunger section 19 in valve seat 3, and through the passages 47 around valve 9 into chamber 5. The amount of material so displaced from chambger 7 is in excess of that required for priming chamber 5, and the excess is forced out through the pump outlet 13. Thus, the pump is a double-acting pump, acting to pump material on both upstrokes and downstrokes without objectionable pulsation in pump delivery.

An important feature of the pump is its low friction characteristics which makes it especially suitable for pumping materials which do not have lubricating qualities. As regards plunger sections 17 and 19, there is considerable clearance between these and the internal walls of cylinder sections 25 and 21, hence no friction between these parts. The only friction which occurs in operation of the pump is between plunger section 17, bushing 33 (which is made as an'anti-friction bushing) and packing 37, and between plunger section 19 and the O-ring O in valve 9. As previously mentioned, there is clearance between valve 9 and the bore of cylinder section 25, the valve being held centered by plunger section 19.

FIG. 4 illustrates a modification having a shovel foot valve at its lower end. instead of a ball check foot valve as in FIG. 2. As shown in FIG. 4, a shovel rod 81 comprising part of piston extends down from the lower end of the lower plunger section 19 through the central opening in the valve seat 57, and carries a shovel 83 on its lower end. This shovel moves upward in extension 61 on each upstroke of the plunger 15 and shovels material upward through the central opening in seat 57 into lower pump chamber 7. The intermediate diameter 17 and the smallest diameter 81 of piston 15 are related so that the volume in chamber 7 increases and decreases by substantially twice the amount of decrease and increase in volume, respectively, of chamber 5 on reciprocation of piston 15. The ball check is replaced by a chopping check valve 35 having a slidable fit on the shovel rod, with packing as indicat d at 87 for making a seal between the valve and the rod.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A pump comprising a cylinder, a valve seat in the cylinder intermediate the length of the cylinder dividing the cylinder into a first chamber toward one end of the cylinder and a second chamber toward the other end of the cylinder, a valve in the first chamber engageable with the seat to close off communication between the chambers, said valve being adapted to open in response to pressure differential between the second chamber and the first chamber for flow from the second to the first chamber, said cylinder having an outlet from the first chamber and a checked inlet for the second chamber, a reciprocable 4 plunger extending into the cylinder from said one end of the cylinder having a first section in the first chamber and a second section of larger cross sectional area than the first section extending through said valve into the second chamber, said second plunger section having a sliding sealing fit in said valve.

2. A pump as set forth in claim 1 wherein said valve seat is an annular valve seat having a central opening, said second plunger section extending through said central opening with space therearound for flow from the second to the first chamber.

3. A pump as set forth in claim 2 wherein said first chamber has an internal shoulder spaced from the valve seat for limiting movement of the valve away from its seat.

4. A pump as set forth in claim 3 wherein said first chamber has a bore of circular cross section between said shoulder and the valve seat and said valve is of polygonal cross section having a clearance fit in said bore and providing passages around the valve to said first chamber when the valve is off the seat.

5. A pump as set forth in claim 4 wherein the checked inlet is at said other end of the cylinder and the outlet is a lateral outlet from the first chamber.

6. A pump as set forth in claim 5 wherein the checked inlet comprises an annular valve seat at said other end of the cylinder, a ball check valve in said second chamber engageable with the latter seat, and a retainer in said sec- 0nd chamber for said ball check valve.

7. A pump as set forth in claim 5 wherein the checked inlet comprises an annular valve seat at said other end of the cylinder, a tubular extension out-ward of the latter seat, a shovel rod extending from the end of the second section of the plunger through the latter seat, a shovel on said rod, and a check valve having a slidable sealing fit on said rod inward of and engageable with the latter seat.

8. A pump comprising a cylinder including a tubular section and a body section threaded on one end of the tubular section constituting the upper end of the tubular section, an annular valve seat in the cylinder at said end of said tubular section and dividing the cylinder into an upper chamber in said body section and a lower chamber in said tubular section, a valve of square cross section slidable in the lower end of the upper chamber toward and away from the seat, said valve being engageable with the seat to close off communication between the chambers and being adapted to move away from the seat in response to pressure differential between the lower chamber and the upper chamber for blow from the lower chamberi to the upper chamber, said cylinder having a lateral outlet from the upper chamber and a checked inlet at the lower end of the lower chamber, a reciprocable plunger extending into the cylinder from the upper end of the upper chamber and having an upper cylindric section in the upper chamber and a lower cylindric section of larger diameter than the upper section extending through said valve into the lower chamber, said second section having a sliding sealing fit in said valve.

9. A pump comprising a cylinder adapted for use in vertical position comprising a cylindric tube, an annular valve seat at the upper end of the tube, a tubular body threaded on the upper end of the tube and holding the valve seat in place, said tube having s checked inlet at its lower end and said body having a lateral outlet, said body defining an upper cylindric chamber above the valve seat and said tube defining a lower cylindric chamber below the valve seat, a valve of square cross section having a clearance lit in the lower end of the upper chamber, said valve having a central opening, spring means biasing said valve downward toward the seat, a head at the upper end of the upper chamber, and a plunger having an upper cylindric section having a sliding sealing lit in the head and a lower cylindric. section of larger diameter than the upper section extending through the central opening in the valve and having a sliding sealing fit therein.

10. A pump as set forth in claim 9 wherein said body has a first internal shoulder adjacent its lower end engaging the valve seat and a second internal shoulder spaced from the first shoulder limiting upward movement of the valve.

11. A pump as set forth in claim & wherein the checked inlet comprises an annular valve seat at said other end of the cylinder, a ball check valve in said second chamber engageable with the latter seat, and a retainer in said sec-nd chamber for said ball check valve.

12. A pump as set forth in claim 9 wherein the checked inlet comprises an annular valve seat at said other end of the cylinder, a tubular extension outward of the latter seat, a shovel rod extending from the end of the second section of the plunger through the latter seat, a shovel on said rod, and a check valve having a slidable sealing fit on said rod inward of and engageable with the latter seat.

13. A double acting pump for high viscosity fluids having two chambers of equal size therein, a piston having a large diameter central portion, a relatively smallerdiameter portion extending into one of said chambers and a still smaller diameter portion extending into the other of said chambers, motor means operably associated with said piston and cylinder for providing relative reciprocal motion between said piston and cylinder, means positioned between and operable in conjunction with said piston and cylinder for transferring the high viscosity fluid from the other of the chambers of said cylinder to the one chamber on movement of said piston relative to said cylinder in one direction, means positioned between and operable in conjunction with said piston and cylinder for permitting entry of high viscosity fluid into said other chamber only during movement of the piston in an opposite direction relative to said cylinder and means for discharging high viscosity fluid from the one chamber on movement of the piston in either of said directions.

14. Structure as set forth in claim 13, wherein the three diameters of the piston are related so that the larger diameter approaches but is smaller than the internal diameter of said cylinder and the intermediate diameter and smallest diameter of the piston are related so that the volume in said other chamber increases and decreases by substantially twice the amount of decrease and increase in volume, respectively, of the one chamber on reciprocation of said piston.

15. Structure as set forth in claim 13 and further including priming structure secured to said cylinder for forcing the high viscosity fluid into said other chamber.

16. A double acting high viscosity fluid pump comprising a pump cylinder having upper and lower portions, a piston reciprocally mounted in said cylinder having a large diameter central portion, an intermediate diameter portion extending out of said cylinder through one end thereof and a small diameter portion extending out of said cylinder through the other end thereof whereby two chambers of diiferent volume are formed in the opposite ends of the cylinder, a check valve positioned between said cylinder portions for permitting high viscosity fluid to pass only from one of said chambers to the other thereof, a chopping check valve in said other end of the cylinder for permitting flow of high viscosity fluid only into said one chamber, priming structure secured to the cylinder adjacent said chopping check valve for forcing fluid into said one chamber only on movement of said piston in one direction, motor means connected to said piston for reciprocating said piston and means for discharging said high viscosity fluid from said other chamber during movement of the pump piston in both directions on reciprocation thereof.

17. A double acting pump for high viscosity fluids comprising a pump cylinder having a substantially uniform inner diameter open at one end and having a discharge orifice at the other end, a piston reciprocally mounted within said cylinder having .a central portion, a smaller diameter portion extending into said other end of the cylinder and a still smaller diameter portion extending into the one end of the cylinder, a check valve positioned over the one end of the cylinder for preventing discharge of material therefrom on movement of the piston toward the one end of the cylinder and a check valve positioned centrally of the cylinder dividing the cylinder into two chambers for preventing movement of material toward said one end of the cylinder on movement of the piston toward the other end of the cylinder while permitting movement of material toward said other end of the cylinder from said one end of the cylinder on movement of the piston toward said one end of the cylinder.

18. Structure as set forth in claim 17 and further including priming means secured to the said one end of the cylinder for forcing material into the chamber at said one end of the cylinder on movement of the piston toward said other end of the cylinder.

References Cited by the Examiner UNITED STATES PATENTS 2,136,636 11/1938 Rotter 103-195 2,636,441 4/1953 Woelfer 103-168 X DONLEY I. STGCKING, Primary Examiner. WARREN E. COLEMAN, Examiner. 

1. A PUMP COMPRISING A CYLINDER, A VALVE SEAT IN THE CYLINDER INTERMEDIATE THE LENGTH OF THE CYLINDER DIVIDING THE CYLINDER INTO A FIRST CHAMBER TOWARD ONE END OF THE CYLINDER AND A SECOND CHAMBER TOWARD THE OTHER END OF THE CYLINDER, A VALVE IN THE FIRST CHAMBER ENGAGEABLE WITH THE SEAT TO CLOSE OFF COMMUNICATION BETWEEN THE CHAMBERS, SAID VALVE BEING ADAPTED TO OPEN IN RESPONSE TO PRESSURE DIFFERENTIAL BETWEEN THE SECOND CHAMBER AND THE FIRST CHAMBER FOR FLOW FROM THE SECOND TO THE FIRST CHAMBER, SAID CYLINDER HAVING AN OUTLET FROM THE FIRST CHAMBER AND A CHECKED INLET FOR THE SECOND CHAMBER, A RECIPROCABLE PLUNGER EXTENDING INTO THE CYLINDER FROM SAID ONE END OF THE CYLINDER HAVING A FIRST SECTION IN THE FIRST CHAMBER AND A SECOND SECTION OF LARGER CROSS SECTION SECTIONAL AREA THAN THE FIRST SECTION EXTENDING THROUGH SAID VALVE INTO THE SECOND CHAMBER, SAID SECOND PLUNGER SECTION HAVING A SLIDING SEALING FIT IN SAID VALVE. 